1. Field of the Invention
The present invention relates to an apparatus which utilizes an energy transmitting liquid for coupling an ultrasonic energy transducer to a target object. One aspect of the present invention is an apparatus for adjustably supporting a container holding the energy transmitting liquid to ensure easy adjustment of the container relative to the target object (i.e. relative to a human body).
2. Description of the Prior Art
Ultrasonic sound waves are those mechanical displacement pressure waves having a frequency above the human ear's audibility limit of approximately 20,000 cycles per second. Such ultrasonic waves have extremely good transmission characteristics through water and other liquids, as well as through many solid objects. In other words, ultrasonic waves can travel over lond distances through such transmitting media without large power losses. However, air and most other gases are not suitable for transmitting ultrasonic waves over long distances because of the rapid power losses which are encountered.
One common use of ultrasonic waves is in sonar applications. Sonar enables one to locate objects submerged in water, such as submarines, by transmitting ultrasonic waves toward the suspected location of the submerged object and then detecting the reflections of the waves from the object. Another use of ultrasonic radiation is to locate flaws in various structural members such as metal I-beams and the like.
Ultrasonic energy has also been widely used in the medical field. One such application involves the use of ultrasonic transducers in diagnostic instruments. In such an application, ultrasonic transducers are used to scan various organs of the human body such as the heart. When the reflections of the ultrasonic waves from the target body organ are recorded and correlated, they give an accurate cross section or profile of the particular organ being studied. This cross section enables a physician to locate abnormalities in the organ. In one sense, such an ultrasonic application is essentially a sonar-type use of ultrasonic waves as applied to the human body.
Another medically related use for ultrasonic energy is in the treatment of various diseased organs or tissues of the body. For example, many types of common ailments, such as arthritis, bursitis, and a wide variety of other afflictions may be improved or alleviated by the localized application of ultrasonic sound waves to the affected tissue. Similarly, ultrasonic sound waves have also been used to destroy various limited groups of cells in the human body.
In some situations the same ultrasonic transducer head can be used for both diagnostic and treatment purposes. The diagnostic function of the transducer is usually accomplished at low level power inputs to the transducer head; the treatment function is usually performed at higher power levels. For example, U.S. Pat. No. 3,237,623 to Gordon discloses such a dual function for a single transducer head.
Regardless of the particular purpose for the ultrasonic waves, it is generally impractical to affix or couple the ultrasonic transducer head directly to the target body tissue to be treated or examined. Similarly, since ultrasonic energy cannot be propagated efficiently through ambient air, the transducer head cannot merely be spaced above the body. Thus, it has been customary in the prior art to utilize a waterbath as a transmitting medium for the transducer head. However, a common characteristic of all prior waterbath structures is that they are somewhat cumbersome to apply and adjust on the body and/or require partial or complete submersion of the target object in the bath.
As shown in U.S. Pat. No. 3,356,086, one common type of therapeutic waterbath structure comprises a flexible, enclosed envelope for containing the energy transmitting liquid. This envelope is designed to be wrapped around the body member to be examined (i.e. an arm). The envelope is then secured in position by various types of fastening tapes or straps. The ultrasonic transducers are attached, usually permanently, to the outside surface of the envelope. A disadvantage of such a waterbath is the difficulty in repositioning the envelope to a different body area. Whenever such a repositioning is desired, the envelope must be loosened from the area around which it was initially placed, and then moved and retied around the new area. This also necessitates a corresponding repositioning of all the electrical lead wires and other apparatus associated with the transducer head. Such an operation is both cumbersome and time-consuming.
Other types of waterbath structures have also been utilized involving relatively rigid containers for holding the energy transmitting liquid. In most cases, the transducer head is fixedly supported by and coupled to the rigid bath structure. Thus, when it is desired to reposition the bath to a different area of the body, all the equipment associated with the transducer must generally be repositioned also. As noted earlier, this is often difficult to accomplish. Consequently, a need exists for a relatively simple apparatus for using an energy transmitting liquid to couple an energy transducer to a human body, the coupling apparatus being relatively easy to reposition.